Various sensors may be applied to a person for measuring physiological parameters indicative of health or wellness. As one example, a pulse oximetry sensor generates a blood-volume plethysmograph waveform from which oxygen saturation of arterial blood and pulse rate may be determined, among other parameters. As another example, an acoustic sensor may be used to detect airflow sounds in the lungs, bronchia or trachea, which are indicative of respiration rate.